opcode.c

lua解释器早期1.0版本

      lua_error ("stack overflow");
      return 1;
     }
    }
    else if (tag(b-1) == T_CFUNCTION)
    {
     int nparam; 
     lua_debugline = 0;			/* always reset debug flag */
     nvalue(b) = (base-stack);		/* store base value */
     base = b+1;
     nparam = top-base;			/* number of parameters */
     (fvalue(b-1))();			/* call C function */
     
     /* shift returned values */
     { 
      int i;
      int nretval = top - base - nparam;
      top = base - 2;
      base = stack + (int) nvalue(base-1);
      for (i=0; i<nretval; i++)
      {
       *top = *(top+nparam+2);
       ++top;
      }
     }
    }
    else
    {
     lua_reportbug ("call expression not a function");
     return 1;
    }
   }
   break;
   
   case RETCODE:
   {
    int i;
    int shift = *pc++;
    int nretval = top - base - shift;
    top = base - 2;
    pc = bvalue(base-2);
    base = stack + (int) nvalue(base-1);
    for (i=0; i<nretval; i++)
    {
     *top = *(top+shift+2);
     ++top;
    }
   }
   break;
   
   case HALT:
   return 0;		/* success */
   
   case SETFUNCTION:
   {
    int file, func;
    file = *((Word *)(pc));
    pc += sizeof(Word);
    func = *((Word *)(pc));
    pc += sizeof(Word);
    if (lua_pushfunction (file, func))
     return 1;
   }
   break;
   
   case SETLINE:
    lua_debugline = *((Word *)(pc));
    pc += sizeof(Word);
   break;
   
   case RESET:
    lua_popfunction ();
   break;
   
   default:
    lua_error ("internal error - opcode didn't match");
   return 1;
  }
 }
}


/*
** Mark all strings and arrays used by any object stored at stack.
*/
void lua_markstack (void)
{
 Object *o;
 for (o = top-1; o >= stack; o--)
  lua_markobject (o);
}

/*
** Open file, generate opcode and execute global statement. Return 0 on
** success or 1 on error.
*/
int lua_dofile (char *filename)
{
 if (lua_openfile (filename)) return 1;
 if (lua_parse ()) { lua_closefile (); return 1; }
 lua_closefile ();
 return 0;
}

/*
** Generate opcode stored on string and execute global statement. Return 0 on
** success or 1 on error.
*/
int lua_dostring (char *string)
{
 if (lua_openstring (string)) return 1;
 if (lua_parse ()) return 1;
 return 0;
}

/*
** Execute the given function. Return 0 on success or 1 on error.
*/
int lua_call (char *functionname, int nparam)
{
 static Byte startcode[] = {CALLFUNC, HALT};
 int i; 
 Object func = s_object(lua_findsymbol(functionname));
 if (tag(&func) != T_FUNCTION) return 1;
 for (i=1; i<=nparam; i++)
  *(top-i+2) = *(top-i);
 top += 2;
 tag(top-nparam-1) = T_MARK;
 *(top-nparam-2) = func;
 return (lua_execute (startcode));
}

/*
** Get a parameter, returning the object handle or NULL on error.
** 'number' must be 1 to get the first parameter.
*/
Object *lua_getparam (int number)
{
 if (number <= 0 || number > top-base) return NULL;
 return (base+number-1);
}

/*
** Given an object handle, return its number value. On error, return 0.0.
*/
real lua_getnumber (Object *object)
{
 if (tonumber (object)) return 0.0;
 else                   return (nvalue(object));
}

/*
** Given an object handle, return its string pointer. On error, return NULL.
*/
char *lua_getstring (Object *object)
{
 if (tostring (object)) return NULL;
 else                   return (svalue(object));
}

/*
** Given an object handle, return a copy of its string. On error, return NULL.
*/
char *lua_copystring (Object *object)
{
 if (tostring (object)) return NULL;
 else                   return (strdup(svalue(object)));
}

/*
** Given an object handle, return its cfuntion pointer. On error, return NULL.
*/
lua_CFunction lua_getcfunction (Object *object)
{
 if (tag(object) != T_CFUNCTION) return NULL;
 else                            return (fvalue(object));
}

/*
** Given an object handle, return its user data. On error, return NULL.
*/
void *lua_getuserdata (Object *object)
{
 if (tag(object) != T_USERDATA) return NULL;
 else                           return (uvalue(object));
}

/*
** Given an object handle and a field name, return its field object.
** On error, return NULL.
*/
Object *lua_getfield (Object *object, char *field)
{
 if (tag(object) != T_ARRAY)
  return NULL;
 else
 {
  Object ref;
  tag(&ref) = T_STRING;
  svalue(&ref) = lua_createstring(lua_strdup(field));
  return (lua_hashdefine(avalue(object), &ref));
 }
}

/*
** Given an object handle and an index, return its indexed object.
** On error, return NULL.
*/
Object *lua_getindexed (Object *object, float index)
{
 if (tag(object) != T_ARRAY)
  return NULL;
 else
 {
  Object ref;
  tag(&ref) = T_NUMBER;
  nvalue(&ref) = index;
  return (lua_hashdefine(avalue(object), &ref));
 }
}

/*
** Get a global object. Return the object handle or NULL on error.
*/
Object *lua_getglobal (char *name)
{
 int n = lua_findsymbol(name);
 if (n < 0) return NULL;
 return &s_object(n);
}

/*
** Pop and return an object
*/
Object *lua_pop (void)
{
 if (top <= base) return NULL;
 top--;
 return top;
}

/*
** Push a nil object
*/
int lua_pushnil (void)
{
 if ((top-stack) >= MAXSTACK-1)
 {
  lua_error ("stack overflow");
  return 1;
 }
 tag(top) = T_NIL;
 return 0;
}

/*
** Push an object (tag=number) to stack. Return 0 on success or 1 on error.
*/
int lua_pushnumber (real n)
{
 if ((top-stack) >= MAXSTACK-1)
 {
  lua_error ("stack overflow");
  return 1;
 }
 tag(top) = T_NUMBER; nvalue(top++) = n;
 return 0;
}

/*
** Push an object (tag=string) to stack. Return 0 on success or 1 on error.
*/
int lua_pushstring (char *s)
{
 if ((top-stack) >= MAXSTACK-1)
 {
  lua_error ("stack overflow");
  return 1;
 }
 tag(top) = T_STRING; 
 svalue(top++) = lua_createstring(lua_strdup(s));
 return 0;
}

/*
** Push an object (tag=cfunction) to stack. Return 0 on success or 1 on error.
*/
int lua_pushcfunction (lua_CFunction fn)
{
 if ((top-stack) >= MAXSTACK-1)
 {
  lua_error ("stack overflow");
  return 1;
 }
 tag(top) = T_CFUNCTION; fvalue(top++) = fn;
 return 0;
}

/*
** Push an object (tag=userdata) to stack. Return 0 on success or 1 on error.
*/
int lua_pushuserdata (void *u)
{
 if ((top-stack) >= MAXSTACK-1)
 {
  lua_error ("stack overflow");
  return 1;
 }
 tag(top) = T_USERDATA; uvalue(top++) = u;
 return 0;
}

/*
** Push an object to stack.
*/
int lua_pushobject (Object *o)
{
 if ((top-stack) >= MAXSTACK-1)
 {
  lua_error ("stack overflow");
  return 1;
 }
 *top++ = *o;
 return 0;
}

/*
** Store top of the stack at a global variable array field. 
** Return 1 on error, 0 on success.
*/
int lua_storeglobal (char *name)
{
 int n = lua_findsymbol (name);
 if (n < 0) return 1;
 if (tag(top-1) == T_MARK) return 1;
 s_object(n) = *(--top);
 return 0;
}

/*
** Store top of the stack at an array field. Return 1 on error, 0 on success.
*/
int lua_storefield (lua_Object object, char *field)
{
 if (tag(object) != T_ARRAY)
  return 1;
 else
 {
  Object ref, *h;
  tag(&ref) = T_STRING;
  svalue(&ref) = lua_createstring(lua_strdup(field));
  h = lua_hashdefine(avalue(object), &ref);
  if (h == NULL) return 1;
  if (tag(top-1) == T_MARK) return 1;
  *h = *(--top);
 }
 return 0;
}


/*
** Store top of the stack at an array index. Return 1 on error, 0 on success.
*/
int lua_storeindexed (lua_Object object, float index)
{
 if (tag(object) != T_ARRAY)
  return 1;
 else
 {
  Object ref, *h;
  tag(&ref) = T_NUMBER;
  nvalue(&ref) = index;
  h = lua_hashdefine(avalue(object), &ref);
  if (h == NULL) return 1;
  if (tag(top-1) == T_MARK) return 1;
  *h = *(--top);
 }
 return 0;
}


/*
** Given an object handle, return if it is nil.
*/
int lua_isnil (Object *object)
{
 return (object != NULL && tag(object) == T_NIL);
}

/*
** Given an object handle, return if it is a number one.
*/
int lua_isnumber (Object *object)
{
 return (object != NULL && tag(object) == T_NUMBER);
}

/*
** Given an object handle, return if it is a string one.
*/
int lua_isstring (Object *object)
{
 return (object != NULL && tag(object) == T_STRING);
}

/*
** Given an object handle, return if it is an array one.
*/
int lua_istable (Object *object)
{
 return (object != NULL && tag(object) == T_ARRAY);
}

/*
** Given an object handle, return if it is a cfunction one.
*/
int lua_iscfunction (Object *object)
{
 return (object != NULL && tag(object) == T_CFUNCTION);
}

/*
** Given an object handle, return if it is an user data one.
*/
int lua_isuserdata (Object *object)
{
 return (object != NULL && tag(object) == T_USERDATA);
}

/*
** Internal function: return an object type. 
*/
void lua_type (void)
{
 Object *o = lua_getparam(1);
 lua_pushstring (lua_constant[tag(o)]);
}

/*
** Internal function: convert an object to a number
*/
void lua_obj2number (void)
{
 Object *o = lua_getparam(1);
 lua_pushobject (lua_convtonumber(o));
}

/*
** Internal function: print object values
*/
void lua_print (void)
{
 int i=1;
 void *obj;
 while ((obj=lua_getparam (i++)) != NULL)
 {
  if      (lua_isnumber(obj))    printf("%g\n",lua_getnumber (obj));
  else if (lua_isstring(obj))    printf("%s\n",lua_getstring (obj));
  else if (lua_iscfunction(obj)) printf("cfunction: %p\n",lua_getcfunction (obj));
  else if (lua_isuserdata(obj))  printf("userdata: %p\n",lua_getuserdata (obj));
  else if (lua_istable(obj))     printf("table: %p\n",obj);
  else if (lua_isnil(obj))       printf("nil\n");
  else			         printf("invalid value to print\n");
 }
}